Most agricultural equipment, particularly, tractors, are fitted with a standard "three point" hitch which attaches to the tractor near the rear axel. A three point hitch comprises two bars, referred to as draw bars, and a third adjustable bar which project outward from the rear of the tractor, are movably mounted, and are spaced apart so as to define a triangular shape. Each draw bar has, at one end, an aperture in which a self aligning ball sleeve is pivotally mounted. A conventional ball sleeve has a generally ring like shape with a curved outer surface. The ball sleeve is mounted within the aperture at the end of the draw bar. This configuration allows the axis of the ball sleeve aperture to, within limitations, pivot with two degrees of freedom or any combination thereof.
The vehicle or implement to be towed, typically a grader or other piece of agricultural equipment, usually contains a standard triangular frame having two pins or studs attached at right angles to the base corners of the frame. The apex of the frame contains a set of holes into which a pin is inserted. FIG. 1 illustrates such a prior art stud 6 secured to an implement frame 8. Stud 6, which is cylindrically shaped, has a bevelled tip 6A at one end and a threaded section 6B over approximately half its length. A circular aperture 6C extends through stud 6 near end 6A for receiving a standard locking pin. Stud 6 is preferably formed of metal and is mechanically coupled to frame 8 in a conventional matter by nuts 12 and 14 and washer 16.
A tractor is typically hitched to a piece of equipment as follows. A draw bar (not shown) and stud 6 are positioned adjacent one another so as to align bevel tip 6A with the ball sleeve of the draw bar. Stud 6 is inserted into the ball sleeve and a locking pin (not shown) is inserted into pin hole 6C to securely fasten frame 8 to the draw bar. These steps are repeated until each stud of frame 8 is aligned and secured to its respective drawbar.
The task of manually aligning the studs with the ball sleeves of the draw bars is time consuming and often difficult. This difficulty is caused by the inability to accurately position the studs within even close proximity of the draw bars. Further, once the stud and draw bar are positioned adjacent one another the rigidity of the draw bar and the frame make it difficult to accurately align the ball sleeve with the axis of the stud, despite the broad angles at which the ball sleeve may be pivoted. Further, alignment of one of the two studs with its respective draw bar may misalign the other stud, particularly if it is not secured to its respective draw bars.
From the above discussion it may be appreciated that there exists a need for an apparatus and method of quickly and efficiently aligning the studs of an implement frame with the draw bars of a hitch assembly.
Accordingly, it is an object of the present invention to provide an improved stud which is more easily aligned with the draw bars of a hitch assembly than prior art studs.
A further object of the present invention is to provide a tool for aligning a stud with the draw bars of a hitch assembly.
Another object of the present invention is to provide an improved stud having a ball shaped tip which may be engaged by an alignment tool from a variety of off axis angles to align the stud with a draw bar of a hitch assembly.
A further object of the present invention is to provide an alignment tool having an internal socket at either or both ends thereof for receiving a stud having a ball shaped tip to facilitate aligning of the stud with the ball sleeve of a hitch assembly draw bar.
Another object of the present invention to provide an alignment assembly for fast and accurately aligning the studs of an implement frame with the drawbars of a hitch assembly.
Still a further object of the present invention is to provide method of aligning a stud with the draw bar of a hitch assembly which is faster and more efficient than prior art methods.
An even further object of the present invention is to provide an improved method of aligning a stud with a hitch assembly draw bar by pivotally engaging the stud with an alignment tool and slidably forcing the drawbar over the alignment tool and onto the stud.